This invention relates to the control of airships in free flight. More particularly, it relates to the propulsion, control, and stabilization of lighter than air miniblimps.
Small airships, especially miniblimps, are in limited use at present. A major reason is that control systems presently available contain many parts such as linkages, gears, a multiplicity of propulsion motors, or are otherwise large and relatively heavy. The traditional approach to airship control has been to use airplane control systems with a resulting use of many components.
With airships, a very small increase in weight causes a significant increase in size. This is because lighter than air gases such as Helium provide approximately 0.07 pounds of lift per cubic foot. Hence, one pound of weight will need over 14 cubic feet of Helium to lift it. This is the factor which up to now has made airships large and bulky. Applicant's novel improvements to airship control will minimize size and weight. It will help to provide a practical miniblimp.
The following survey of prior art will show presently available control systems:
1. Wolfe shows a remotely controlled toy space ship in U.S. Pat. No. 3,292,304. For control it requires three drive motors, and is tethered. The extra drive motors require more weight than a single drive motored system. The tether is required since no control surfaces are provided for stability. This system is for tethered flight, and not suitable for freeflight.
2. Lawrence teaches pivoting motors as "accessory steering ascending and descending means," in U.S. Pat. No. 1,879,345. However, the many motors required, and the accessory rudders required are large and heavy, necessitating an impractically large airship.
3. Ragner, in "Build Control Line Blimp with your Soldering Iron," American Modeler, April, 1961 teaches how to build a toy blimp for tethered flight. The toy does not have a control means, in that the motor is fixed as are the four fins. It is impractical for free flight.
4. Seeman, et.al., in "Remotely Piloted Miniblimps," Astronautics and Aeronautics, February 1974 give a good discussion of the need for the miniblimp. However, the propulsion and control system for the airship is large and therefor heavy. Four control surfaces are provided, with movement causing elements for control (presumably). A large motor is provided with braces and other devices. The result is high weight, high cost, and impracticability.
5. Hines, in U.S. Pat. No. 1,869,256 describes a "combination flying machine and airship." Hines teaches the using of a propeller to function as a rudder. However, his invention requires separate motors for raising and lowering the airship. This multiplicity of motors requires much weight, requiring a large airship, and leading to an impractical device.
6. Waller, in U.S. Pat. No. 2,131,155 describes a single drive motor or engine for propulsion and to reduce the need for a vertical steering rudder. Waller still requires moveable control surfaces. Also, Waller neglects to provide a stabilizing surface or stabilizing means about the yaw axis a necessary feature in any practical airship or aircraft. Further, the plurality of brackets, gears, guide wires, and frame elements is such that the total weight has made the airship impractical for miniblimps.
What is needed is an airship control system of minimum size, complexity, and weight.
An object of the present invention is to provide an airship control system of minimum size, complexity and weight.